We’ve seen lakes turn green because of algae and mildew, but since the 1960s, Chicago has been greening its river every year for the city’s St. Patrick’s Day Parade.
Apparently, local plumbers found out they could dye the water green by accident:
In 1961 [Chicago Journeymen Plumbers Local Union business manager] Stephen Bailey was approached by a plumber who was wearing some…coveralls [which] had been mostly stained or dyed a perfect shade of green… [W]hen Stephen Bailey asked how the coveralls got this way, they discovered that the dye used to detect leaks into the river turned green, not just any color green, but the perfect color green.
The men then decided to use the perfect “Irish green” to surprise the public on St. Patrick’s Day.
But the greening of the Chicago River didn’t come without difficulties. The dyeing committee not only had to turn the river green, but be green as well.
Dan Lydon explains:
One of the initial problems was that there was no recipe for dying rivers green. Chicago was the first and only city to do it. So the question was: Do you use a few handfuls of dye or a carload?
One hundred pounds was used the first year. The river stayed green for a week! The second year, 1963, we cut to 50 lbs., and the river was green for three days.
We finally decided to use 25 lbs. and that did the job for one day.
In 1966, the environmentalists accused the parade committee of polluting the river. They complained that the dye was oil-based and was detrimental to all living things….
The committee experimented with a number of vegetable dyes and after a bit of trial and error, the current 40 lbs. of new dye was hit upon. It produces a carpet of green for four or five hours. The flamboyant Bailey had a field day with the press when he announced he was changing the Chicago River to the Shannon River for one day.
Today Mike Butler and his crew (with the help of a leprechaun, they say) are responsible for turning the river this “perfect” color.
- Nat Geo Expeditions
Photos: Ken Ilio via Flickr